Chapter 3 - Jawless Vertebrates

A fish is an aquatic vertebrate that respires using gills, is ectothermic, has fins, and
has a skin that is usually with scales. The taxonomic term for fish is Pisces,
which, as you should know, is a paraphyletic group.

PISCES: the fishes:
they may be paraphyletic, but they are still fish. This Florida Museum of
Natural History
web site gives a basic introduction to the major groups of fishes (with good
photographs showing characteristic features).

Web Site with more information

Here is a terrific web site on FISHES
from the Biomedia section of the Biological Sciences Website;
Glasgow University Zoology Museum.

Although people generally use the word "fish" for both singular and plural, most
scientists
usually make a distinction between them. From the scientist's point of view, then,
what's
the difference between "fish" and "fishes"?

Both words can refer to more than one fish. The word "fishes" refers to more
than one
KIND of fish: If you have a tub with three bluegills in it, say: "I have
several fish in this tub."

If you have a bucket with a bluegill, a largemouth bass, and a paddlefish in it, say:
"I have several fishes in this tub."

And remember, a linguist will tell you that all languages constantly change over time and
space, which means that what was "right" yesterday in Texas may not be
"right"
tomorrow in Maine! "